Degradable Polymer for Chewing Gum

ABSTRACT

There is provided a chewing gum comprising at least one chewing gum polyester polymer, wherein at least a first part of said polyester polymer is obtainable by condensation polymerization and at least a further part of said polyester polymer is obtainable by ring-opening polymerization.

FIELD OF THE INVENTION

The present invention relates to the field of chewing gum and chewinggum polymers.

TECHNICAL BACKGROUND AND PRIOR ART

U.S. Pat. No. 5,672,367 describes polyester polymers obtainable by thepolymerisation of cyclic esters. Explicitly is disclosed a co-polymerconsisting of D,L-lactide and ε-caprolactone with a glass transitiontemperature (Tg) of 15° C. (Example 1) and a copolymer consisting ofD,L-lactide and ε-caprolactone with a glass transition temperature (Tg)of −10° C. (Example 2).

Another approach within the same technical field is represented anddisclosed by WO 02/076232. This document discloses a branched polymerstructure for the purpose of obtaining the desired properties of thepolymer.

A problem, related to polyester polymers obtainable by polymerization ofcyclic esters of the above-disclosed type, is that such polymers, whenused in chewing gum, generally lacks the desired elastomeric propertiesand may be somewhat difficult to match with conventional well-knownpolymers.

It is an object of the invention to provide a chewing gum polyesterpolymer having improved properties suitable for chewing gum.

It is a further object of the invention to provide a chewing gumpolyester polymer having improved elastomeric properties suitable forchewing gum.

SUMMARY OF THE INVENTION

The present invention relates to chewing gum comprising at least onechewing gum polyester polymer, wherein at least a first part of saidpolyester polymer is obtainable by condensation polymerization and atleast a further part of said polyester polymer is obtainable byring-opening polymerization.

According to an embodiment of the invention, the individual first andfurther parts of the polyester polymer may form somewhat continuousparts or blocks of the polymer chain. According to a further embodimentof the invention, the first and further parts of the polyester polymermay appear somewhat more intermittent with respect to each other,meaning that the polymer chain may comprise the first and further partsinterchangeably and/or in randomized order.

According to the invention, advantageous features of both the first andfurther part of the polyester polymer may be paired, and a resultingpolyester polymer may be obtained having properties relevant for chewinggum which were out of reach when applying pure polymers of the twotypes.

One advantageous property of a polyester according to an embodiment ofthe invention is that the advantageous elastomeric properties recognizedin connection with polyester obtainable by condensation polymerizationmay be optimized with respect to biodegradability when incorporatingmonomers comprising cyclic esters, cyclic carbonates, carboxylic acids,alcohols, or combinations thereof in the polymer chain(s).

In an embodiment of the invention, said at least one polyester polymeris at least partly biodegradable.

The biodegradability of the polyester polymer of the present invention,may be comparable to the biodegradability of prior art biodegradablepolyester polymers, as it is basically comprised of the same orcorresponding monomer types. In an embodiment of the invention, saidcondensation polymerization is based on polyfunctional monomers selectedfrom the group of alcohols and acids.

Advantageous features of the first part of the polymer comprisesadvantageous elastomeric properties, advantageous amorph performance atlow Tg and advantageous compatibility with polymers, both biodegradableor conventional, which may be applied in a chewing gum polymer system.In this context it should be noted that a chewing gum polymer system maycomprise quite complex structures where one polymer is specificallydedicated for the purpose of matching another polymer or other polymers;e.g. one polymer may be plasticizing one or more other polymers.

In an embodiment of the invention, the polyfunctional monomers includedi-, tri- or higher-functional alcohols or esters thereof and di-, tri-or higher-functional aliphatic or aromatic carboxylic acids or estersthereof. Moreover, also hydroxy acids or anhydrides and halides ofpolyfunctional carboxylic acids may be used as monomers.

In an embodiment of the invention, said condensation polymerization isbased on polyfunctional monomers selected from the group of alcohols,carboxylic acids, hydroxycarboxylic acids, or derivatives thereof.

According to a preferred embodiment of the invention, alcohols andcarboxylic acids forms the basis of the first part of the polyester.

In an embodiment of the invention, said ring-opening polymerization isbased on cyclic ester monomers, cyclic carbonate monomers orcombinations thereof.

According to the invention, the further part of the polymer may beformed on the basis of cyclic esters, cyclic carbonates or combinationsthereof, thereby obtaining advantages such as higher Tg. Moreover, anadvantageous biodegradability with well documented residues may beobtained, which is quite important when considering both environmentaland health due to the fact that such residues may ultimately appear bothin the environment during degradation of the chewing gum polymer andeven, in some degree, in the mouth of a user. In this context it shouldalso be noted that polymers of the further part type has also provedcompatibility with other polymers of a chewing gum system.

In an embodiment of the invention, at least one of said monomers isdi-functional.

When one or more di-functional compounds, i.e. compounds containing twofunctional groups in each molecule, are applied as monomers anadvantageous embodiment of the invention is obtained because suchdifunctional compounds may impart linear and crystalline parts in thepolymer.

In an embodiment of the invention, at least one of said monomers is atleast tri-functional.

When one or more tri-functional monomers comprise at least threefunctional groups in each molecule an advantageous embodiment of theinvention is obtained because such trifunctional monomers may impartbranching of the polymer.

In an embodiment of the invention, the molar ratio between the monomersforming said first and further part of the polyester polymer is withinthe range of 1:1000 and 1000:1 by weight.

In an embodiment of the invention, the monomers forming said first partof the polyester polymer comprises a molar content within the range of 1to 99% of said polyester polymer.

Thus, in an embodiment of the invention, said first part of thepolyester polymer comprises a molar content within the range of 1 to 99%of said polyester polymer.

In an embodiment of the invention, the monomers forming said furtherpart of the polyester polymer comprises a molar content within the rangeof 1 to 99% of said polyester polymer.

Thus, in an embodiment of the invention, said further part of thepolyester polymer comprises a molar content within the range of 1 to 99%of said polyester polymer.

In an embodiment of the invention, said at least one chewing gumpolyester polymer forms the sole polymer of the chewing gum.

According to an embodiment of the invention, the chewing gum polyesterpolymer of the present invention may be described as a hybrid polyesterpolymer and may form the sole polymer of the chewing gum due to the factthat the polymer per se may comprise the desired hybrid functionality ofa given chewing gum system.

In an embodiment of the invention, said first part of the at least onepolyester polymer comprises a molar content within the range of 30 to90%, preferably within the range of 50 to 70% of said polyester polymer.

In an embodiment of the invention, said first part of the polyesterpolymer comprises within the range of 30 to 90%, preferably within therange of 50 to 70% by weight of said polyester polymer.

In an embodiment of the invention, the molar ratio or the weight ratiobetween the first part of the polyester polymer and further part of thepolyester polymer is in the range of 30:70 to 90:10, whereby thepolyester polymer may be provided with a combination of elastomer andelastomer plasticizing properties. In other words the polyester polymermay be applicable as an elastomeric and at the same time resinouscompound in the chewing gum of the invention.

In an embodiment of the invention, said at least one chewing gumpolyester polymer forms one of further polymers of the chewing gum.

In an embodiment of the invention, the further polymers may be anyconventional chewing gum polymers, biodegradable as well assubstantially non-degradable, such as conventional synthetic or naturalresins and elastomers.

In an embodiment of the invention, said at least one chewing gumpolyester polymer forms one of further polyester polymers of the chewinggum.

In an embodiment of the invention, the further polyester polymer may bea further hybrid chewing gum polyester polymer according to theinvention, or alternatively a conventional polyester polymer obtained byeither condensation polymerization or ring-opening polymerization.

Thus, in an embodiment of the invention, the chewing gum of the presentinvention may additionally to the abovementioned hybrid polyesterpolymer(s) comprising a first and further part, moreover comprise one ormore prior art biodegradable polymers, such as e.g. those disclosed inWO 02/076230, WO 2004/028269, WO 02/076227, WO 02/076228, WO2004/028265, WO 2004/028269, and WO 2004/028270.

In an embodiment of the invention, said first part of the at least onepolyester polymer comprises a molar content within the range of 1 to70%, preferably within the range of 20 to 60% of said polyester polymer.

In an embodiment of the invention, said first part of the polyesterpolymer comprises within the range of 1 to 70%, preferably within therange of 20 to 60% by weight of said polyester polymer.

In an embodiment of the invention, the molar ratio or the weight ratiobetween the first part of the polyester polymer and further part of thepolyester polymer is in the range of 1:99 to 70:30, whereby thepolyester polymer may be provided with elastomer plasticizingproperties. In other words the polyester polymer may be applicable as aresinous compound in the chewing gum of the invention, which may furthercomprise a resinous compound.

In an embodiment of the invention, said first part of the at least onepolyester polymer comprises a molar content within the range of 40 to99%, preferably within the range of 50 to 90% of said polyester polymer.

In an embodiment of the invention, said first part of the polyesterpolymer comprises within the range of 40 to 99%, preferably within therange of 50 to 90% by weight of said polyester polymer.

In an embodiment of the invention, the molar ratio or the weight ratiobetween the first part of the polyester polymer and further part of thepolyester polymer is in the range of 40:60 to 99:1, whereby thepolyester polymer may be provided with elastomer properties. In otherwords the polyester polymer may be applicable as an elastomeric compoundin the chewing gum of the invention.

In an embodiment of the invention, said at least one polyester polymercomprises a polyester selected from the group comprising copolymers,terpolymers, quaterpolymer, graftpolymers, blockpolymers, randomizedpolymers, and combinations thereof.

In an embodiment of the invention, said at least one polyester polymercomprises a block copolymer or a randomized copolymer.

In an embodiment of the invention, said at least one polyester copolymerhas at least two glass transition temperatures.

A glass transition temperature refers herein to the average temperaturein a glass transition temperature range.

In an embodiment of the invention, the chewing gum polyester polymer mayhave two glass transition temperatures as measured by dynamic mechanicalanalysis (DMA), while the same polymer may seem to have only one glasstransition temperature as measured by differential scanning calorimetry(DSC).

In an embodiment of the invention, said at least one polyester copolymerhas a single glass transition temperature.

In an embodiment of the invention, said polyfunctional alcohol monomersare selected from the group comprising glycols, glycerols, polyglycolsand polyglycerols.

In an embodiment of the invention, said polyfunctional alcohol monomerscontain 2 to 100 carbon atoms in the main chain.

In an embodiment of the invention, said polyfunctional alcohol monomersare selected from the group comprising ethylene glycol, 1,2-propanediol,1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol,diethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol,neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol,sorbitol, mannitol, and mixtures thereof.

In an embodiment of the invention, said polyfunctional alcoholderivative monomers are selected from the group comprising triacetin,glycerol palmitate, glycerol sebacate, glycerol adipate, tripropionin,and mixtures thereof.

In an embodiment of the invention, said polyfunctional carboxylic acidmonomers are selected from the group comprising saturated, unsaturated,aliphatic, or aromatic polyfunctional carboxylic acids, or combinationsthereof.

In an embodiment of the invention, said polyfunctional carboxylic acidmonomers contain 2 to 100 carbon atoms, preferably 4 to 18 carbon atomsin the main chain.

In an embodiment of the invention, said polyfunctional carboxylic acidmonomers are selected from the group comprising oxalic acid, malonicacid, citric acid, succinic acid, malic acid, tartaric acid, fumaricacid, maleic acid, glutaric acid, glutamic acid, adipic acid, glucaricacid, pimelic acid, suberic acid, azelaic acid, sebacic acid,dodecanedioic acid, cyclopropane dicarboxylic acid, cyclobutanedicarboxylic acid, cyclohexane dicarboxylic acid, terephthalic acid,isophthalic acid, phthalic acid, trimellitic acid, pyromellitic acid,naphthalene 1,4-, 2,3-, 2,6-dicarboxylic acids, and mixtures thereof.

In an embodiment of the invention, said polyfunctional carboxylic acidderivative monomers are selected from the group comprising hydroxyacids, esters, anhydrides, or halides of carboxylic acids, and mixturesthereof.

In an embodiment of the invention, said polyfunctional carboxylic acidderivative monomers are selected from the group comprising 3-hydroxypropionic acid, 6-hydroxycaproic acid, dimethyl or diethyl oxalate,dimethyl or diethyl malonate, dimethyl or diethyl succinate, dimethyl ordiethyl fumarate, dimethyl or diethyl maleate, dimethyl or diethylglutarate, dimethyl or diethyl adipate, dimethyl or diethyl pimelate,dimethyl or diethyl suberate, dimethyl or diethyl azelate, dimethyl ordiethyl sebacate, dimethyl or diethyl dodecanedioate, dimethyl ordiethyl terephthalate, dimethyl or diethyl isophthalate, dimethyl ordiethyl phthalate, and mixtures thereof.

In an embodiment of the invention, said ring-opening polymerisation isbased on cyclic monomers selected from the group comprising glycolides,lactides, lactones, cyclic carbonates or mixtures thereof.

In an embodiment of the invention, said lactide monomers are selectedfrom the group comprising L-lactide, D,L-lactide, and mesolactide, orcombinations thereof.

In an embodiment of the invention, said lactone monomers are selectedfrom the group comprising ε-caprolactone, δ-valerolactone,γ-butyrolactone, and β-propiolactone, or mixtures thereof.

In an embodiment of the invention, said cyclic carbonate monomers areselected from the group comprising trimethylene carbonates, dioxanones,ethylene carbonates, propylene carbonates, monocabonates, dioxepanones,or mixtures thereof.

In an embodiment of the invention, said chewing gum comprises one ormore chewing gum ingredients selected from the group comprisingflavoring agents, sweetening agents, fillers, softeners, emulsifiers,and active ingredients.

In an embodiment of the invention, said flavoring agents comprisenatural and synthetic flavorings in the form of natural vegetablecomponents, essential oils, essences, extracts, powders, including acidsand other substances capable of affecting the taste profile.

In an embodiment of the invention, said chewing gum comprises flavor inan amount of 0.01 to about 25 wt %, preferably in an amount of 0.1 toabout 5 wt %, said percentage being based on the total weight of thechewing gum.

In an embodiment of the invention, the chewing gum comprises at leastone softener in an amount of about 0 to about 20% by weight of thechewing gum, more typically about 0 to about 10% by weight of thechewing gum.

According to the present invention, softener may advantageously be addedto the chewing gum of the present invention in an amount correspondingto the amount used in conventional chewing gum.

In an embodiment of the invention, the softeners may be selected amongtallow, hydrogenated tallow, hydrogenated and partially hydrogenatedvegetable oils, cocoa butter, glycerol monostearate, glyceroltriacetate, lecithin, mono-, di- and triglycerides, acetylated mono- ordiglycerides, fatty acids—such as stearic, palmitic, oleic and linoleicacids, waxes, PGE and mixtures thereof.

In an embodiment of the invention, the amount of emulsifier is in therange of 0 to 18% by weight of the chewing gum.

In different embodiments of the present invention, the chewing gum maybe provided either with or without emulsifier.

In an embodiment of the invention, said sweetening agents are selectedfrom the group comprising bulk sweeteners, and high intensitysweeteners, and combinations thereof.

In an embodiment of the invention, the chewing gum comprises sugar.

In an embodiment of the invention, the chewing gum is sugar free. In anembodiment of the invention, said bulk sweeteners comprises an amount ofabout 5 to about 95%, preferably about 20 to about 80% by weight of thechewing gum.

According to the invention, the bulk sweeteners may be sugar sweeteners,non-sugar sweeteners and combinations thereof.

In an embodiment of the invention, the sugar sweeteners may comprisesaccharide-containing compounds such as sucrose, dextrose, maltose,dextrins, trehalose, D-tagatose, dried invert sugar, fructose, levulose,galactose, corn syrup solids, alone or in combination.

Moreover, in an embodiment of the invention, the non-sugar sweetenersmay comprise sugar alcohols such as sorbitol, mannitol, xylitol,hydrogenated starch hydrolysates, maltitol, isomaltol, erythritol,lactitol, alone or in combination.

In an embodiment of the invention, the chewing gum comprises highintensity sweeteners in an amount of about 0 to about 1.2%, preferablyabout 0.1 to about 0.6% by weight of the chewing gum.

In an embodiment of the invention, the high intensity sweeteners maycomprise sucralose, aspartame, salts of acesulfame, alitame, neotame,twinsweet, saccharin and its salts, cyclamic acid and its salts,glycyrrhizin, dihydrochalcones, thaumatin, monellin, stevioside, aloneor in combination

In an embodiment of the invention, the chewing gum comprises filler inan amount of about 0 to about 50% by weight of the chewing gum, moretypically about 10 to about 40% by weight of the chewing gum.

In an embodiment of the invention, the chewing gum comprises at leastone coloring agent.

In an embodiment of the invention, said chewing gum ingredients compriseactive ingredients.

In an embodiment of the invention, the active ingredients may beselected among medicines, oral compositions, anti-smoking agents, highlypotent sweeteners, pH adjusting agents, nutrients, antiseptics,minerals, agents for care or treatment of the oral cavity and the teeth,dietary supplements, other active ingredients and combinations thereof.

In an embodiment of the invention, said chewing gum is coated with anouter coating selected from the group comprising hard coating, softcoating and edible film-coating.

The outer coating may be a sugar coating or a sugarless coating or acombination thereof.

In an embodiment of the invention, the outer coating is a hard coatingcomprising at least 50% by weight of a polyol selected from the groupcomprising sorbitol, maltitol, mannitol, xylitol, erythritol, lactitoland isomalt.

In a further embodiment of the invention, the edible film-coatingcomprises at least one component selected from the group comprising waxand an edible film-forming agent such as a cellulose derivative, amodified starch, a dextrin, gelatine, shellac, gum arabic, zein, avegetable gum, a synthetic polymer and any combination thereof.

In an embodiment of the invention, the outer coating comprises at leastone additive component selected from the group comprising a bindingagent, a moisture absorbing component, a film forming agent, adispersing agent, an antisticking component, a bulking agent, aflavouring agent, a coloring agent, a pharmaceutically or cosmeticallyactive component, a lipid component, a wax component, a sugar, an acidand an agent capable of accelerating the after-chewing degradation ofthe degradable polymers.

In an embodiment of the invention, the agent capable of acceleratingafter-chewing degradation of the degradable polymers may be one or moreenzymes selected among those mentioned in PCT/DK2003/000939.

In an embodiment of the invention, said chewing gum polyester polymer isobtainable by said condensation polymerization performed first and saidring-opening polymerization performed afterwards.

The resulting chewing gum polyester polymers are unique compared tothose polyester polymers, which may by obtained by either condensationpolymerization or ring-opening polymerization alone.

The uniqueness is based on the fact that combinations of monomers may beprepared that are not or only with difficulty obtainable by either typeof polymerization alone.

According to an embodiment of the present invention, chewing gumpolyester polymers featuring advantageous properties may be obtained,when an initial condensation polymerization is followed by aring-opening polymerization to form a block polymer, wherein at leastone of the blocks results from condensation polymerization and at leasttwo further blocks result from ring-opening polymerization. The at leasttwo last-mentioned blocks may physically be located at two ends of thefirst block and may in some embodiments be bonded or crosslinked.

Furthermore in an embodiment of the invention, the first block may beeither linear or branched. When a first polycondensation block (andprepolymer) is branched, the resulting polymer may comprise severalblocks, because a subsequent ring-opening polymerization may haveseveral starting points on the branched prepolymer.

In an embodiment of the invention, said chewing gum polyester polymer isobtainable by said condensation polymerization and said ring-openingpolymerization performed randomized.

According to an embodiment of the invention, a chewing gum polyesterpolymer provided by such a randomized polymerization may feature uniqueelastomeric and/or resinous properties. In some preferred embodiments,the chewing gum polyester polymer provided by randomized condensationand ring-opening polymerization may embody advantageous textureproperties for chewing gum purposes.

In an embodiment of the invention, said polyester polymer is obtained bya combination of condensation polymerization and ring-openingpolymerization.

In an embodiment of the invention, at least a first part of the monomersof said polyester polymer are polymerized by condensationpolymerization, and at least a further part of the monomers of saidpolyester polymer are polymerized by ring-opening polymerization.

Moreover, the invention relates to a method of obtaining a chewing gumpolyester polymer, whereby condensation polymerization and ring-openingpolymerization are combined.

Furthermore, the invention relates to a method of obtaining a chewinggum, whereby the polyester polymer is obtained through a combinedcondensation polymerization and ring-opening polymerization.

In an embodiment of the invention, the polyester polymer is obtainedthrough a combined condensation polymerization and ring-openingpolymerization.

In an embodiment of the invention, said condensation polymerization andsaid ring-opening polymerization are performed subsequently.

The method according to the invention may result in polyester polymers,which are unique compared to those polyester polymers, which may byobtained by either condensation polymerization or ring-openingpolymerization alone.

Uniqueness of the resulting polymer is based on the fact that it maycomprise combinations of monomers that are not or only with difficultyobtainable by either type of polymerization alone.

In an embodiment of the invention, said condensation polymerization iscarried out to prepare a prepolymer, which is afterwards used forinitiation of a ring-opening polymerization.

In an embodiment of the invention, it may be an advantage to run the twopolymerization reactions subsequently in order to establish optimalprocess conditions for each type of polymerization. One of the factors,which needs to be controlled, is the temperature. A problem relating totemperature is that some advantageous cyclic compounds would break downif exposed to a temperature high enough to carry out condensationpolymerization of some also advantageous alcohols and carboxylic acids.According to an embodiment of the invention, a way to solve this problemis to first carry out a condensation polymerization to a certain degreeand then lower the temperature before supplying the cyclic compounds andproceeding with the ring-opening polymerization.

In a further embodiment of the invention, the molecular weight obtainedby condensation polymerization is advantageously controlled in order toprepare an oligomer or prepolymer, which is applicable as a macroinitiator for the subsequent ring-opening polymerization.

Benefits of using the product from a condensation polymerization asinitiator for ring-opening polymerization include: Convenient process,unique possibilities of mixing the two different groups of monomers,preparation of a polymer with alternating regions of monomer unitsoriginating from condensation polymerization and ring-openingpolymerization, respectively.

The present invention makes it possible to control the features, e.g.crystallinity, of the obtained polymer in a new way by combining thecharacteristics of polycondensation polyesters and ring-openingpolymerization polyesters. In this way, the crystallinity may beadjusted by design of the chain length in the alternating regions ofeither polyester type.

In an embodiment of the invention, said condensation polymerization andsaid ring-opening polymerization are performed randomized.

In an embodiment of the invention, advantageous properties of thechewing gum polyester polymer may be obtained, when the twopolymerization techniques are performed simultaneously or by and by in arandomized order.

DETAILED DISCLOSURE

It is a major objective of the present invention to provide a chewinggum polymer, which results in chewing gum products that followingchewing are more readily degraded in the environment than conventionalchewing gum and furthermore which, relative to chewing gum comprisingconventional non-degradable polymers, may be removed more readilymechanically and/or by the use of cleaning agents. The easierelimination of the chewing gum of the present invention may be of greatadvantage, when the chewing gum is improperly dropped or discarded byusers.

According to an embodiment of the invention, the chewing gum comprisesone or more polyester polymers, which may be regarded as biodegradable,and hence causes the chewing gum to be more readily degraded and/orremoved from surfaces, where it has been dumped.

According to a preferred definition of biodegradability according to theinvention, biodegradability is a property of certain organic moleculeswhereby, when exposed to the natural environment or placed within aliving organism, they react through an enzymatic or microbial process,often in combination with a chemical process such as hydrolysis, to formsimpler compounds, and ultimately carbon dioxide, nitrogen oxides,methane, water and the like.

In the present context the term ‘biodegradable polymers’ meansenvironmentally or biologically degradable polymer compounds and refersto chewing gum base components which, after dumping the chewing gum, arecapable of undergoing a physical, chemical and/or biologicaldegradation, whereby the dumped chewing gum waste becomes more readilyremovable from the site of dumping or is eventually disintegrated tolumps or particles, which are no longer recognizable as being chewinggum remnants. The degradation or disintegration of such degradablepolymers may be effected or induced by physical factors such astemperature, light, moisture, etc., by chemical factors such asoxidative conditions, pH, hydrolysis, etc. or by biological factors suchas microorganisms and/or enzymes. The degradation products may be largeroligomers, trimers, dimers and monomers.

Preferably, the ultimate degradation products are small inorganiccompounds such as carbon dioxide, nitrogen oxides, methane, ammonia,water, etc.

As referred to herein, the glass transition temperature (Tg) may bedetermined by for example DSC (DSC: differential scanning calorimetry).The DSC may generally be applied for determining and studying of thethermal transitions of a polymer and specifically, the technique may beapplied for the determination of a second order transition of amaterial. The transition at Tg is regarded as such a second ordertransition, i.e. a thermal transition that involves a change in heatcapacity, but does not have a latent heat. Hence, DSC may be applied forstudying Tg.

Unless otherwise indicated, as used herein with regard to polymers, theterm “molecular weight” means number average molecular weight (Mn) ing/mol. Furthermore, as used herein the short form PD designates thepolydispersity of polymers, polydispersity being defined as Mw/Mn, whereMw is the weight average molecular weight of a polymer. Awell-established technique for characterization of biodegradablepolymers is gel permeation chromatography (GPC).

In general, a chewing gum composition typically comprises awater-soluble bulk portion, a water-insoluble chewable gum base portionand flavouring agents. The water-soluble portion dissipates with aportion of the flavouring agent over a period of time during chewing.The gum base portion is retained in the mouth throughout the chew. Theterm chewing gum refers to both a chewing and bubble type gum in itsgeneral sense.

The gum base is the masticatory substance of the chewing gum, whichimparts the chew characteristics to the final product. The gum basetypically defines the release profile of flavors and sweeteners andplays a significant role in the gum product.

The insoluble portion of the gum typically may contain any combinationof elastomers, vinyl polymers, elastomer plasticizers, waxes, softeners,fillers and other optional ingredients such as colorants andantioxidants.

The composition of gum base formulations can vary substantiallydepending on the particular product to be prepared and on the desiredmasticatory and other sensory characteristics of the final product.However, typical ranges (% by weight) of the above gum base componentsare: 5 to 80% by weight elastomeric compounds, 5 to 80% by weightelastomer plasticizers, 0 to 40% by weight of waxes, 5 to 35% by weightsoftener, 0 to 50% by weight filler, and 0 to 5% by weight ofmiscellaneous ingredients such as antioxidants, colourants, etc.

Elastomers provide the rubbery, cohesive nature to the gum, which variesdepending on this ingredient's chemical structure and how it may becompounded with other ingredients. Elastomers suitable for use in thegum base and gum of the present invention may include natural orsynthetic types.

Elastomer plasticizers vary the firmness of the gum base. Theirspecificity on elastomer inter-molecular chain breaking (plasticizing)along with their varying softening points cause varying degrees offinished gum firmness and compatibility when used in base. This may beimportant when one wants to provide more elastomeric chain exposure tothe alkanic chains of the waxes.

According to an embodiment of the invention, the polyester polymer ofthe present invention may substitute or supplement conventionalnon-degradable elastomers and/or elastomer plasticizers in chewing gum.The fundamental characteristics of the polyester polymer of the presentinvention render it possible to achieve a polymer embracing bothelastomeric and resinous properties in the same polymer, oralternatively to promote either elastomeric or resinous properties inseparate polymers, each of which are variations of the polyester polymerof the present invention.

According to an embodiment of the invention, one or more polyesterpolymers of the present invention may replace natural resins andelastomers, and may also substitute conventional synthetic resins andelastomers.

Without being limited to theory, it is believed that one suitablestrategy for creation of biodegradable polymers, which may substituteconventional either elastomers or resins, may be to prepare polyesterpolymers of the present invention with molecular weights and glasstransition temperatures equivalent to the conventional elastomers orresins, which are to be replaced in the chewing gum of the presentinvention.

A preferred conventional chewing gum elastomer to replace may e.g. be asynthetic elastomer, such as polyisobutylene (PIB) of molecular weight(Mn) about 30000 g/mol to 120000 g/mol and Tg about −20 to −70° C.

Correspondingly, a preferred conventional chewing gum elastomerplasticizer to replace may be the synthetic resin, low molecular weightpolyvinyl acetate (PVA) of molecular weight (Mn) about 2000-15000 g/moland Tg about 20-35° C.

A further suitable strategy according to an embodiment of the inventionmay be the creation of single polymers of the present invention havingboth resinous and elastomeric properties. This is a possibility arisingfrom the fact, that the polyester polymer of the present invention ispolymerized by two different polymerization techniques following eachother. Such a polyester polymer of the present invention possessing bothelastomeric and elastomer plasticizing properties may thereforesubstitute a resinous and an elastomeric compound at the same time.

As a result, a chewing gum may according to an embodiment of theinvention be created on the basis of one single polyester polymer of thepresent invention.

In another embodiment of the invention, the resulting chewing gum maycomprise the inventive chewing gum polyester polymer along with anunconventionally small amount of individual elastomers and/or resins.

A chewing gum polyester polymer of the present invention having featuressubstituting resinous as well as elastomeric compounds, herein sometimesreferred to as a hybrid polyester polymer, may in an embodiment of theinvention have intermediate Tg and molecular weight with respect to theTg and molecular weights of conventional elastomers or resins alone. Inan alternative embodiment, the hybrid polymer may have more than one Tgresulting from the different parts in the polymer.

Generally, the chewing gum of the present invention may comprise one ormore chewing gum polyester polymers, and each of these polyesterpolymers may comprise a first and a further part. The first part may beobtained from condensation polymerization, while the further part may beobtained from ring-opening polymerization. According to an embodiment ofthe invention, the first and further parts may be recognized as blocksin the chewing gum polyester polymer, or alternatively as regions,monomers and/or residues of the first and further part locatedrandomized throughout the polyester polymer.

The first part of the chewing gum polyester polymers of the inventionmay thus be recognized as originating from condensation polymerizationand they may comprise elastomeric properties, which may impart anelastomeric function in the chewing gum. Similarly, the further part ofthe polyester polymer, i.e. the part originating from ring-openingpolymerization, may comprise elastomer plasticizing properties, whichmay impart a resinous-like function in the chewing gum. Consequently,such a polyester polymer comprising a first and further part asdescribed may bring about outstanding opportunities within the art ofbiodegradable chewing gum. Excellent properties of the chewing gum maybe obtained when applying at least one of these hybrid polyesterpolymers comprising both elastomeric and resinous properties.

According to an embodiment of the invention, the first part of thechewing gum polyester polymer may be prepared through reaction of atleast one alcohol or derivative thereof and at least one acid orderivative thereof.

Generally, according to an embodiment of the invention, the first partof the chewing gum polyester polymer may be prepared by step-growthpolymerization of di-, tri- or higher-functional alcohols or estersthereof with di-, tri- or higher-functional aliphatic or aromaticcarboxylic acids or esters thereof. Likewise, also hydroxy acids oranhydrides and halides of polyfunctional carboxylic acids may be used asmonomers. The polymerization of the first part of the chewing gumpolyester polymer of the present invention may involve directpolyesterification or transesterification and may be catalyzed. Use ofbranched monomers suppresses the crystallinity of this polyester part.Mixing of dissimilar monomer units along the chain also suppressescrystallinity. To control the reaction and the molecular weight of thefirst part of the chewing gum polyester polymer according to theinvention, it is possible to stop the polymer chains by addition ofmonofunctional alcohols or acids and/or to utilize a stoichiometricimbalance between acid groups and alcohol groups or derivatives ofeither. Furthermore, the polymerization reaction may be continued with aring-opening polymerization by the supply of cyclic monomers andreaction conditions as outlined and exemplified herein to form a furtherpart of the chewing gum polyester polymer of the present invention.Hereby a hybrid polyester polymer may be prepared, which along thechains comprises repeating units originating from both acids, alcoholsand cyclic monomers.

According to an embodiment of the invention, the preparation of thefirst part of the chewing gum polyester polymer of the present inventionmay also involve the adding of long chain aliphatic carboxylic acids oraromatic monocarboxylic acids, which may be used to control the degreeof branching in the polymer, and conversely, multifunctional monomersmay be used to create branching.

In an embodiment of the invention, the polymerization process may befollowed by at least a partial endcapping of the free hydroxyl andcarboxyl groups by monofunctional compounds.

In general, polyfunctional carboxylic acids, which according to thepresent invention may be part of the monomers forming the first part ofthe chewing gum polyester polymer of the invention, are high-meltingsolids that have very limited solubility in the polycondensationreaction medium. Often esters or anhydrides of the polyfunctionalcarboxylic acids may be used to overcome this limitation.Polycondensations involving carboxylic acids or anhydrides produce wateras the condensate, which requires high temperatures to be driven off.Thus, polycondensations involving transesterification of the ester of apolyfunctional acid are often the preferred process. For example, thedimethyl ester of terephthalic acid may be used instead of terephtlialicacid itself. In this case, methanol rather than water is condensed, andthe former can be driven off more easily than water. In addition to anester derivative an anhydride or a halide of the carboxylic acid mayalso be used under certain circumstances.

In an embodiment of the invention, the reaction forming the first partof the polyester polymer of the present invention may usually be carriedout in the bulk (no solvent). High temperatures and vacuum may be usedto remove the by-product and drive the reaction to completion or to adesired intermediate state forming a suitable starting point for thering-opening polymerization forming the further part of the chewing gumpolyester polymer of the present invention. Because of the cyclicmonomers such as lactide or glycolide being especially temperaturesensitive, the temperature in the reaction medium must be carefullycontrolled in order to avoid a temperature increase above the damagingtemperature limit existing for certain applied cyclic monomers, whilethese cyclic monomers are present in the reaction medium.

In general, for preparation of the first part of the chewing gumpolyester polymer of the present invention, the preferred polyfunctionalcarboxylic acids or derivatives thereof are either saturated orunsaturated aliphatic or aromatic and contain 2 to 100 carbon atoms andmore preferably 4 to 18 carbon atoms. In the polymerization of the firstpart of the chewing gum polyester polymer of the present invention someapplicable examples of carboxylic acids, which may be employed as suchor as derivatives thereof, include aliphatic polyfunctional carboxylicacids such as oxalic, malonic, citric, succinic, malic, tartaric,fumaric, maleic, glutaric, glutamic, adipic, glucaric, pimelic, suberic,azelaic, sebacic, dodecanedioic acid, etc. and cyclic aliphaticpolyfunctional carboxylic acids such as cyclopropane dicarboxylic acid,cyclobutane dicarboxylic acid, cyclohexane dicarboxylic acid, etc. andaromatic polyfunctional carboxylic acids such as terephthalic,isophthalic, phthalic, trimellitic, pyromellitic and naphthalene 1,4-,2,3-, 2,6-dicarboxylic acids and the like. For the purpose ofillustration and not limitation, some examples of carboxylic acidderivatives include hydroxy acids such as 3-hydroxy propionic acid and6-hydroxycaproic acid and anhydrides, halides or esters of acids, forexample dimethyl or diethyl esters, corresponding to the alreadymentioned acids, which means esters such as dimethyl or diethyl oxalate,malonate, succinate, fumarate, maleate, glutarate, adipate, pimelate,suberate, azelate, sebacate, dodecanedioate, terephthalate,isophthalate, phthalate, etc. Generally speaking, methyl esters aresometimes more preferred than ethyl esters due to the fact that higherboiling alcohols are more difficult to remove than lower boilingalcohols.

Moreover, for preparation of the first part of the chewing gum polyesterpolymer of the present invention, the usually preferred polyfunctionalalcohols contain 2 to 100 carbon atoms as for instance polyglycols andpolyglycerols. In the polymerization process of the first part of thechewing gum polyester polymer of the present invention some applicableexamples of alcohols, which may be employed as such or as derivativesthereof, includes polyols such as ethylene glycol, 1,2-propanediol,1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol,diethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol,neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol,sorbitol, mannitol, etc. For the purpose of illustration and notlimitation, some examples of alcohol derivatives include triacetin,glycerol palmitate, glycerol sebacate, glycerol adipate, tripropionin,etc.

Additionally, with regard to polymerization of the first part of thechewing gum polyester polymer of the present invention, thechain-stoppers sometimes used are monofunctional compounds. They arepreferably either mono alcohols containing 1-20 carbon atoms ormonocarboxylic acids containing 2-26 carbon atoms. General examples aremedium or long-chain fatty alcohols or acids, and specific examplesinclude mono alcohols such as methanol, ethanol, butanol, hexanol,octanol, etc. and lauryl alcohol, myristyl alcohol, cetyl alcohol,stearyl alcohol, stearic alcohol, etc. and monocarboxylic acids such asacetic, lauric, myristic, palmitic, stearic, arachidic, cerotic,dodecylenic, palmitoleic, oleic, linoleic, linolenic, ericic, benzoic,naphthoic acids and substituted napthoic acids, 1-methyl-2 naphthoicacid and 2-isopropyl-1-naphthoic acid, etc.

In an embodiment of the invention, an acid catalyst or atransesterification catalyst is used in the polymerization of the firstpart of the chewing gum polyester polymer of the present invention, andnon-limiting examples of those are the metal catalysts such as acetatesof manganese, zinc, calcium, cobalt or magnesium, and antimony-(III)oxide, germanium oxide or halide and tetraalkoxygermanium, titaniumalkoxide, zinc or aluminum salts.

According to an embodiment of the invention, the further part of thechewing gum polyester polymer may be prepared from at least one or morecyclic monomers such as glycolides, lactides, lactones, cycliccarbonates or mixtures thereof.

According to an embodiment of the invention, the lactides may includeL-lactide, D,L-lactide, and mesolactide. Likewise, the lactone monomersmay be chosen among ε-caprolactone, δ-valerolactone, γ-butyrolactone,and β-propiolactone. The lactones may further include ε-caprolactones,δ-valerolactones, γ-butyrolactones, or β-propiolactones that have beensubstituted with one or more alkyl or aryl substituents at anynon-carbonyl carbon atoms along the ring, including compounds in whichtwo substituents are contained on the same carbon atom.

Furthermore, in an embodiment of the invention, the carbonate monomersmay be selected from the following group: Trimethylene carbonate,5-alkyl-1,3-dioxan-2-one, 5,5-dialkyl-1,3-dioxan-2-one, or5-alkyl-5-alkyloxycarbonyl-1,3-dioxan-2-one, ethylene carbonate,3-ethyl-3-hydroxymethyl, propylene carbonate, trimethylolpropanemonocarbonate, 4,6-dimethyl-1,3-propylene carbonate, 2,2-dimethyltrimethylene carbonate, and 1,3-dioxepan-2-one and mixtures thereof.

The polymerization process of the further part of the chewing gumpolyester polymer of the present invention may take place in thepresence of at least one appropriate catalyst such as metal catalysts,of which stannous octoate is a non-limiting example. Moreover thepolymerization of the further part of the chewing gum polyester polymerof the present invention may be initiated by initiators such as polyols,polyamines or other molecules with multiple hydroxyl or other reactivegroups and mixtures thereof. Yet, in a preferred embodiment of theinvention, the polymerization of the further part of the chewing gumpolyester polymer of the present invention may be initated by aprepolymer, which is polymerized by polycondensation, and which may formthe first part of the chewing gum polyester polymer of the presentinvention.

In accordance with the general principles in manufacturing a chewing gumwithin the scope of the invention, variations of different suitableingredients are listed and explained below.

The chewing gum according to the invention may comprise coloring agents.According to an embodiment of the invention, the chewing gum maycomprise color agents and whiteners such as FD&C-type dyes and lakes,fruit and vegetable extracts, titanium dioxide and combinations thereof.

Further useful chewing gum base components include antioxidants, e.g.butylated hydroxytoluene (BHT), butyl hydroxyanisol (BHA), propylgallateand tocopherols, and preservatives.

In an embodiment of the invention, the chewing gum comprises softenersin an amount of about 0 to about 18% by weight of the chewing gum, moretypically about 0 to about 12% by weight of the chewing gum.

Softeners/emulsifiers may according to the invention be added both inthe chewing gum and the gum base.

A gum base formulation may, in accordance with the present invention,comprise one or more softening agents e.g. sucrose esters includingthose disclosed in WO 00/25598, which is incorporated herein byreference, tallow, hydrogenated tallow, hydrogenated and partiallyhydrogenated vegetable oils, cocoa butter, degreased cocoa powder,glycerol monostearate, glyceryl triacetate, lecithin, mono-, di- andtriglycerides, acetylated monoglycerides, fatty acids (e.g. stearic,palmitic, oleic and linoleic acids) and combinations thereof. As usedherein the term “softener” designates an ingredient, which softens thegum base or chewing gum formulation and encompasses waxes, fats, oils,emulsifiers, surfactants and solubilisers.

To soften the gum base further and to provide it with water-bindingproperties, which confer to the gum base a pleasant smooth surface andreduce its adhesive properties, one or more emulsifiers is/are usuallyadded to the composition, typically in an amount of 0 to 18% by weight,preferably 0 to 12% by weight of the gum base. Mono- and diglycerides ofedible fatty acids, lactic acid esters and acetic acid esters of mono-and diglycerides of edible fatty acids, acetylated mono anddiglycerides, sugar esters of edible fatty acids, Na-, K-, Mg- andCa-stearates, lecithin, hydroxylated lecithin and the like are examplesof conventionally used emulsifiers which can be added to the chewing gumbase. In case of the presence of a biologically or pharmaceuticallyactive ingredient as defined below, the formulation may comprise certainspecific emulsifiers and/or solubilisers in order to disperse andrelease the active ingredient.

Waxes and fats are conventionally used for the adjustment of theconsistency and for softening of the chewing gum base when preparingchewing gum bases. In connection with the present invention, anyconventionally used and suitable type of wax and fat may be used, suchas for instance rice bran wax, polyethylene wax, petroleum wax (refinedparaffin and microcrystalline wax), paraffin, beeswax, carnauba wax,candelilla wax, cocoa butter, degreased cocoa powder and any suitableoil or fat, as e.g. completely or partially hydrogenated vegetable oilsor completely or partially hydrogenated animal fats.

In an embodiment of the invention, the chewing gum comprises filler.

A chewing gum base formulation may, if desired, include one or morefillers/texturisers including as examples, magnesium and calciumcarbonate, sodium sulphate, ground limestone, silicate compounds such asmagnesium and aluminum silicate, kaolin and clay, aluminum oxide,silicium oxide, talc, titanium oxide, mono-, di- and tri-calciumphosphates, cellulose polymers, such as wood, and combinations thereof.

In an embodiment of the invention, the chewing gum comprises filler inan amount of about 0 to about 50% by weight of the chewing gum, moretypically about 10 to about 40% by weight of the chewing gum.

In addition to a water insoluble gum base portion, a typical chewing gumincludes a water soluble bulk portion and one or more flavouring agents.The water-soluble portion may include bulk sweeteners, high intensitysweeteners, flavouring agents, softeners, emulsifiers, colours,acidulants, fillers, antioxidants, and other components that providedesired attributes.

Suitable bulk sweeteners include both sugar and non-sugar sweeteningcomponents. Bulk sweeteners typically constitute from about 5 to about95% by weight of the chewing gum, more typically about 20 to about 80%by weight such as 30 to 60% by weight of the gum.

Useful sugar sweeteners are saccharide-containing components commonlyknown in the chewing gum art including, but not limited to, sucrose,dextrose, maltose, dextrins, trehalose, D-tagatose, dried invert sugar,fructose, levulose, galactose, corn syrup solids, and the like, alone orin combination.

Sorbitol can be used as a non-sugar sweetener. Other useful non-sugarsweeteners include, but are not limited to, other sugar alcohols such asmannitol, xylitol, hydrogenated starch hydrolysates, maltitol,isomaltol, eiythritol, lactitol and the like, alone or in combination.

High-intensity artificial sweetening agents can also be used alone or incombination with the above sweeteners. Preferred high-intensitysweeteners include, but are not limited to sucralose, aspartame, saltsof acesulfame, alitame, neotame, twinsweet, saccharin and its salts,cyclamic acid and its salts, glycyrrhizin, dihydrochalcones, thaumatin,monellin, stevioside and the like, alone or in combination. In order toprovide longer lasting sweetness and flavor perception, it may bedesirable to encapsulate or otherwise control the release of at least aportion of the artificial sweetener. Techniques such as wet granulation,wax granulation, spray drying, spray chilling, fluid bed coating,coasceivation, encapsulation in yeast cells and fiber extrusion may beused to achieve the desired release characteristics. Encapsulation ofsweetening agents can also be provided using another chewing gumcomponent such as a resinous compound.

Usage level of the high intensity artificial sweetener will varyconsiderably and will depend on factors such as potency of thesweetener, rate of release, desired sweetness of the product, level andtype of flavor used and cost considerations. Thus, the active level ofhigh potency artificial sweetener may vary from about 0 to about 8% byweight, preferably 0.001 to about 5% by weight. When carriers used forencapsulation are included, the usage level of the encapsulatedsweetener will be proportionately higher.

Combinations of sugar and/or non-sugar sweeteners can be used in thechewing gum formulation processed in accordance with the invention.Additionally, the softener may also provide additional sweetness such asaqueous sugar or alditol solutions.

If a low-calorie gum is desired, a low-caloric bulking agent can beused. Examples of low caloric bulking agents include polydextrose,Raftilose, Raftilin, fructooligosaccharides (NutraFlora®), palatinoseoligosaccharides; guar gum hydrolysates (e.g. Sun Fiber®) orindigestible dextrins (e.g. Fibersol®). However, other low-caloriebulking agents can be used.

The chewing gum according to the present invention may contain aromaagents and flavoring agents including natural and synthetic flavoringse.g. in the form of natural vegetable components, essential oils,essences, extracts, powders, including acids and other substancescapable of affecting the taste profile. Examples of liquid and powderedflavorings include coconut, coffee, chocolate, vanilla, grape fruit,orange, lime, menthol, liquorice, caramel aroma, honey aroma, peanut,walnut, cashew, hazelnut, almonds, pineapple, strawberry, raspberry,tropical fruits, cherries, cinnamon, peppermint, wintergreen, spearmint,eucalyptus, and mint, fruit essence such as from apple, pear, peach,strawberry, apricot, raspberry, cherry, pineapple, and plum essence. Theessential oils include peppermint, spearmint, menthol, eucalyptus, cloveoil, bay oil, anise, thyme, cedar leaf oil, nutmeg, and oils of thefruits mentioned above.

The chewing gum flavor may be a natural flavoring agent, which isfreeze-dried, preferably in the form of a powder, slices or pieces orcombinations thereof. The particle size may be less than 3 mm, less than2 mm or more preferred less than 1 mm, calculated as the longestdimension of the particle. The natural flavoring agent may in a formwhere the particle size is from about 3 μm to 2 mm, such as from 4 μm to1 mm. Preferred natural flavoring agents include seeds from fruit e.g.from strawberry, blackberry and raspberry.

Various synthetic flavors, such as mixed fruit flavors may also be usedin the present chewing gum centers. As indicated above, the aroma agentmay be used in quantities smaller than those conventionally used. Thearoma agents and/or flavors may be used in the amount from 0.01 to about30% by weight of the final product depending on the desired intensity ofthe aroma and/or flavor used. Preferably, the content of aroma/flavor isin the range of 0.2 to 3% by weight of the total composition.

In an embodiment of the invention, the flavoring agents comprise naturaland synthetic flavorings in the form of natural vegetable components,essential oils, essences, extracts, powders, including acids and othersubstances capable of affecting the taste profile.

Further chewing gum ingredients, which may be included in the chewinggum according to the present invention, include surfactants and/orsolubilisers, especially when pharmaceutically or biologically activeingredients are present. As examples of types of surfactants to be usedas solubilisers in a chewing gum composition according to the invention,reference is made to H. P. Fiedler, Lexikon der Hilfstoffe fürPharmacie, Kosmetik und Angrenzende Gebiete, pages 63-64 (1981) and thelists of approved food emulsifiers of the individual countries. Anionic,cationic, amphoteric or non-ionic solubilisers can be used. Suitablesolubilisers include lecithin, polyoxyethylene stearate, polyoxyethylenesorbitan fatty acid esters, fatty acid salts, mono and diacetyl tartaricacid esters of mono and diglycerides of edible fatty acids, citric acidesters of mono and diglycerides of edible fatty acids, saccharose estersof fatty acids, polyglycerol esters of fatty acids, polyglycerol estersof interesterified castor oil acid (E476), sodium stearoyllatylate,sodium lauryl sulfate and sorbitan esters of fatty acids andpolyoxyethylated hydrogenated castor oil (e.g. the product sold underthe trade name CREMOPHOR), block copolymers of ethylene oxide andpropylene oxide (e.g. products sold under trade names PLURONIC andPOLOXAMER), polyoxyethylene fatty alcohol ethers, polyoxyethylenesorbitan fatty acid esters, sorbitan esters of fatty acids andpolyoxyethylene steraric acid esters.

Particularly suitable solubilisers are polyoxyethylene stearates, suchas for instance polyoxyethylene(8)stearate andpolyoxyethylene(40)stearate, the polyoxyethylene sorbitan fatty acidesters sold under the trade name TWEEN, for instance TWEEN 20(monolaurate), TWEEN 80 (monooleate), TWEEN 40 (monopalmitate), TWEEN 60(monostearate) or TWEEN 65 (tristearate), mono and diacetyl tartaricacid esters of mono and diglycerides of edible fatty acids, citric acidesters of mono and diglycerides of edible fatty acids, sodiumstearoyllatylate, sodium laurylsulfate, polyoxyethylated hydrogenatedcastor oil, blockcopolymers of ethylene oxide and propyleneoxide andpolyoxyethylene fatty alcohol ether. The solubiliser may either be asingle compound or a combination of several compounds. In the presenceof an active ingredient, the chewing gum may preferably also comprise acarrier known in the art.

Emulsifiers, which are used as softeners may include tallow,hydrogenated tallow, hydrogenated and partially hydrogenated vegetableoils, cocoa butter, glycerol monostearate, glycerol triacetate,lechithin, mono-, di- and triglycerides, acetylated monoglycerides,fatty acids (e.g. stearic, palmitic, oleic and linoleic acids), andcombinations thereof.

According to an embodiment of the invention, the chewing gum maycomprise a pharmaceutically, cosmetically or biologically activesubstance. Examples of such active substances, a comprehensive list ofwhich is found e.g. in WO 00/25598, which is incorporated herein byreference,

The active agents to be used in connection with the present inventionmay be any substance desired to be released from the chewing gum. If anaccelerated rate of release is desired, corresponding to the effectobtained for the flavor, the primary substances are those with limitedwater solubility, typically below 10 g/100 ml including substances whichare entirely water insoluble. Examples are medicines, dietarysupplements, oral compositions, anti-smoking agents, highly potentsweeteners, pH adjusting agents, etc.

Further examples of active ingredients include paracetamol, benzocaine,cinniarizine, menthol, carvone, caffeine, chlorhexidine-di-acetate,cyclizine hydrochloride, 1,8-cineol, nandrolone, miconazole, mystatine,aspartame, sodium fluoride, nicotine, saccharin, cetylpyridiniumchloride, other quaternary ammonium compounds, vitamin E, vitamin A,vitamin D, glibenclamide or derivatives thereof, progesterone,acetylsalicylic acid, dimenhydrinate, cyclizine, metronidazole, sodiumhydrogencarbonate, the active components from ginkgo, the activecomponents from propolis, the active components from ginseng, methadone,oil of peppermint, salicylamide, hydrocortisone or astemizole.

Examples of active agents in the form of dietary supplements are forinstance salts and compounds having the nutritive effect of vitamin B2(riboflavin), B12, folinic acid, niacine, biotine, poorly solubleglycerophosphates, amino acids, the vitamins A, D, E and K, minerals inthe form of salts, complexes and compounds containing calcium,phosphorus, magnesium, iron, zinc, copper, iodine, manganese, chromium,selenium, molybdenum, potassium, sodium or cobalt.

Furthermore, reference is made to lists of nutrients accepted by theauthorities in different countries such as for instance US code ofFederal Regulations, Title 21, Section 182.5013.182 5997 and182.8013-182.8997.

Examples of active agents in the form of compounds for the care ortreatment of the oral cavity and the teeth, are for instance boundhydrogen peroxide and compounds capable of releasing urea duringchewing.

Examples of active agents in the form of antiseptics are for instancesalts and compounds of guanidine and biguanidine (for instancechlorhexidine diacetate) and the following types of substances withlimited water-solubility: quaternary ammonium compounds (for instanceceramine, chloroxylenol, crystal violet, chloramine), aldehydes (forinstance paraformaldehyde), compounds of dequaline, polynoxyline,phenols (for instance thymol, para chlorophenol, cresol)hexachlorophene, salicylic anilide compounds, triclosan, halogenes(iodine, iodophores, chloroamine, dichlorocyanuric acid salts), alcohols(3,4 dichlorobenzyl alcohol, benzyl alcohol, phenoxyethanol,phenylethanol), cf. furthermore Martindale, The Extra Pharmacopoeia,28th edition, page 547-578; metal salts, complexes and compounds withlimited water-solubility, such as aluminium salts, (for instancealuminium potassium sulfate AIK (S04) 2, 12H20) and furthermore salts,complexes and compounds of boron, barium, strontium, iron, calcium,zinc, (zinc acetate, zinc chloride, zinc gluconate), copper (copperchloride, copper sulfate), lead, silver, magnesium, sodium, potassium,lithium, molybdenum, vanadium should be included; other compositions forthe care of mouth and teeth: for instance; salts, complexes andcompounds containing fluorine (such as sodium fluoride,sodiummonofluorophosphate, aminofluorides, stannous fluoride),phosphates, carbonates and selenium.

Cf. furthermore J. Dent. Res. Vol. 28 No. 2, page 160-171, 1949, whereina wide range of tested compounds are mentioned.

Examples of active agents in the form of agents adjusting the pH in theoral cavity include for instance: acceptable acids, such as adipinicacid, succinic acid, fumaric acid, or salts thereof or salts of citricacid, tartaric acid, malic acid, acetic acid, lactic acid, phosphoricacid and glutaric acid and acceptable bases, such as carbonates,hydrogen carbonates, phosphates, sulfates or oxides of sodium,potassium, ammonium, magnesium or calcium, especially magnesium andcalcium.

Examples of active agents in the form of anti-smoking agents include forinstance: nicotine, tobacco powder or silver salts, for instance silveracetate, silver carbonate and silver nitrate.

Further examples of active agents are medicines of any type.

Examples of active agents in the form of medicines include caffeine,salicylic acid, salicyl amide and related substances (acetylsalicylicacid, choline salicylate, magnesium salicylate, sodium salicylate),paracetamol, salts of pentazocine (pentazocine hydrochloride andpentazocinelactate), buprenorphine hydrochloride, codeine hydrochlorideand codeine phosphate, morphine and morphine salts (hydrochloride,sulfate, tartrate), methadone hydrochloride, ketobemidone and salts ofketobemidone (hydrochloride), beta-blockers, (propranolol), calciumantagonists, verapamil hydrochloride, nifedinpine as well as suitablesubstances and salts thereof mentioned in Pharm. Int., Nov. 85, pages267-271, Barney H. Hunter and Robert L. Talbert, nitroglycerine,erythrityl tetranitrate, strychnine and salts thereof, lidocaine,tetracaine hydrochloride, etorphine hydrochloride, atropine, insulin,enzymes (for instance papain, trypsin, amyloglucosidase, glucoseoxidase,streptokinase, streptodornase, dextranase, alpha amylase), polypeptides(oxytocin, gonadorelin, (LH. RH), desmopressin acetate (DDAVP),isoxsuprine hydrochloride, ergotamine compounds, chloroquine (phosphate,sulfate), isosorbide, demoxytocin, heparin.

Other active ingredients include beta-lupeol, Letigen, Sildenafilcitrate and derivatives thereof.

Dental products include Carbami, CPP Caseine Phospho Peptide;Chlorhexidine, Chlorhexidine diacetate, Chlorhexidine Chloride,Chlorhexidine digluconate, Hexetedine, Strontium chloride, PotassiumChloride, Sodium bicarbonate, Sodium carbonate, Fluor containingingredients, Fluorides, Sodium fluoride, Aluminium fluoride, Ammoniumfluoride, Calcium fluoride, Stannous fluoride, Other fluor containingingredients Ammonium fluorosilicate, Potassium fluorosilicate, Sodiumfluorosilicate, Ammonium monofluorphosphate, Calcium monofluorphosphate,Potassium monofluorphosphate, Sodium monofluorphosphate, OctadecentylAmmonium fluoride, Stearyl Trihydroxyethyl PropylenediamineDihydrofluoride, Vitamins include A, B1, B2, B6, B12, Folin acid,niacin, Pantothensyre, biotine, C, D, E, K.

Minerals include Calcium, phosphor, magnesium, iron, Zink, Cupper, Iod,Mangan, Crom, Selene, Molybden. Other active ingredients include:Q10@,enzymes. Natural drugs including Ginkgo Biloba, ginger, and fish oil.The invention also relates to use of migraine drugs such as Serotoninantagonists: Sumatriptan, Zolmitriptan, Naratriptan, Rizatriptan,Eletriptan; nausea drugs such as Cyclizin, Cinnarizin, Dimenhydramin,Difenhydrinat; hay fever drugs such as Cetrizin, Loratidin, pain reliefdrugs such as Buprenorfin, Tramadol, oral disease drugs such asMiconazol, Amphotericin B, Triamcinolonaceton; and the drugs Cisaprid,Domperidon, Metoclopramid.

Active ingredients may comprise the below-mentioned compounds orderivates thereof but are not limited thereto: Acetaminophen,Acetylsalicylsyre Buprenoiphine Bromhexin Celcoxib Codeine,Diphenhlydramin, Diclofenac, Etoricoxib, Ibuprofen, Indometacin,Ketoprofen, Lumiracoxib, Morphine, Naproxen, Oxycodon, Parecoxib,Piroxicam, Pseudoefedrin, Rofecoxib, Tenoxicam, Tramadol, Valdecoxib,Calciumcarbonat, Magaldrate, Disulfuram, Bupropion, Nicotine,Azithromycin, Clarithromycin, Clotrimazole, Erythromycin, Tetracycline,Granisetron, Ondansetron, Prometazin, Tropisetron, Brompheniramine,Ceterizin, leco-Ceterizin, Chlorcyclizine, Chlorpheniramin,Chlorpheniramin, Difenhydramine, Doxylamine, Fenofenadin, Guaifenesin,Loratidin, des-Loratidin, Phenyltoloxamine, Promethazin, Pyridamine,Terfenadin, Troxerutin, Methyldopa, Methylphenidate, Benzalcon.Chloride, Benzeth. Chloride, Cetylpyrid. Chloride, Chlorhexidine,Ecabet-sodium, Haloperidol, Allopurinol, Colchinine, Theophylline,Propanolol, Prednisolone, Prednisone, Fluoride, Urea, Miconazole, Actot,Glibenclamide, Glipizide, Metformin, Miglitol, Repaglinide,Rosiglitazone, Apomorfin, Clalis, Sildenafil, Vardenafil, Diphenoxylate,Simethicone, Cimetidine, Famotidine, Ranitidine, Ratinidine, cetrizin,Loratadine, Aspirin, Benzocaine, Dextrometorphan, Ephedrine,Phenylpropanolamine, Pseudoephedrine, Cisapride, Domperidone,Metoclopramide, Acyclovir, Dioctylsulfosucc, Phenolphtalein,Almotriptan, Eletriptan, Ergotamine, Migea, Naratriptan, Rizatriptan,Sumatriptan, Zolmitriptan, Aluminum salts, Calcium salts, Ferro salts,Silver salts, Zinc-salts, Amphotericin B, Chlorhexidine, Miconazole,Triamcinolonacetonid, Melatonine, Phenobarbitol, Caffeine,Benzodiazepiner, Hydroxyzine, Meprobamate, Phenothiazine, Buclizine,Brometazine, Cinnarizine, Cyclizine, Difenhydramine, Dimenhydrinate,Buflomedil, Amphetamine, Caffeine, Ephedrine, Orlistat, Phenylephedrine,Phenylpropanolamin, Pseudoephedrine, Sibutramin, Ketoconazole,Nitroglycerin, Nystatin, Progesterone, Testosterone, Vitamin B12,Vitamin C, Vitamin A, Vitamin D, Vitamin E, Pilocarpin,Aluminumaminoacetat, Cimetidine, Esomeprazole, Famotidine, Lansoprazole,Magnesiumoxide, Nizatide and or Ratinidine.

In one embodiment of the invention, the flavor may be used as tastemasking in chewing gum comprising active ingredients, which bythemselves has undesired taste or which alter the taste of theformulation.

The chewing gum may optionally contain usual additives, such as bindingagents, acidulants, fillers, coloring agents, preservatives, andantioxidants, for instance butylated hydroxytoluene (BHT), butylhydroxyanisol (BHA), propylgallate and tocopherols.

Colorants and whiteners may include FD & C-type dyes and lakes, fruitand vegetable extracts, titanium dioxide, and combinations thereof.

Materials to be used for the above-mentioned encapsulation methods forsweeteners might e.g. include Gelatine, Wheat protein, Soya protein,Sodium caseinate, Caseine, Gum arabic, Mod. starch, Hydrolyzed starches(maltodextrines), Alginates, Pectin, Carregeenan, Xanthan gum, Locusbean gum, Chitosan, Bees wax, Candelilla wax, Carnauba wax, Hydrogenatedvegetable oils, Zein and/or Sucrose.

In general, chewing gum may be manufactured by sequentially adding thevarious chewing gum ingredients to a commercially available mixer knownin the art. After the initial ingredients have been thoroughly mixed,the chewing gum mass is discharged from the mixer and shaped into thedesired form such as by rolling into sheets and cutting into sticks,extruded into chunks or casting into pellets.

Generally, the ingredients may be mixed by first melting the gum baseand adding it to the running mixer. Colors, active agents and/oremulsifiers may also be added at this time. A softener such as glycerinmay also be added at this time, along with syrup and a portion of thebulking agent/sweetener. Further portions of the bulking agent/sweetenermay then be added to the mixer. A flavoring agent is typically addedwith the final portion of the bulking agent/sweetener. A high-intensitysweetener is preferably added after the final portion of bulking agentand flavor have been added.

The entire mixing procedure typically takes from five to fifteenminutes, but longer mixing times may sometimes be required. Thoseskilled in the art will recognize that many variations of the abovedescribed procedure may be followed. Including the one-step methoddescribed in US patent application 2004/0115305 hereby incorporated asreference. Chewing gums are formed by extrusion, compression, rollingand may be centre filled with liquids and/or solids in any form.

The chewing gum according to the present invention may also be providedwith an outer coating, which may be a hard coating, a soft coating, afilm coating, or a coating of any type that is known in the art, or acombination of such coatings. The coating may typically constitute 0.1to 75 percent by weight of a coated chewing gum piece.

One preferred outer coating type is a hard coating, which term isincluding sugar coatings and sugar-free (or sugarless) coatings andcombinations thereof. The object of hard coating is to obtain a sweet,crunchy layer, which is appreciated by the consumer and to protect thegum centers. In a typical process of providing the chewing gum centerswith a protective sugar coating the gum centers are successively treatedin suitable coating equipment with aqueous solutions of crystallisablesugar such as sucrose or dextrose, which, depending on the stage ofcoating reached, may contain other functional ingredients, e.g. fillers,colors, etc.

In one presently preferred embodiment, the coating agent applied in ahard coating process is a sugarless coating agent, e.g. a polyolincluding as examples sorbitol, maltitol, mannitol, xylitol, erythritol,lactitol and isomalt or e.g. a mono- di-saccharide including as exampletrehalose.

Or alternatively a sugarfree soft coating e.g. comprising alternatelyapplying to the centres a syrup of a polyol or a mono- di-saccharide,including as examples sorbitol, maltitol, mannitol, xylitol, erythritol,lactitol, isomalt and trehalose.

In further useful embodiments a film coating is provided by film-formingagents such as a cellulose derivative, a modified starch, a dextrin,gelatine, zein, shellec, gum arabic, a vegetable gum, a syntheticpolymer, etc. or a combination thereof.

In an embodiment of the invention, the outer coating comprises at leastone additive component selected from the group comprising of a bindingagent, a moisture-absorbing component, a film-forming agent, adispersing agent, an antisticking component, a bulking agent, aflavoring agent, a coloring agent, a pharmaceutically or cosmeticallyactive component, a lipid component, a wax component, a sugar, an acid

A coated chewing gum center according to the invention may have anyform, shape or dimension that permits the chewing gum center to becoated using any conventional coating process.

The gum centre of coated chewing gum element according to the inventioncan have any form, shape or dimension that permits the chewing gumcentre to be coated using any conventional coating process. Accordingly,the gum centre may be e.g. in a form selected from a pellet, acushion-shaped pellet, a stick, a tablet, a chunk, a pastille, a pill, aball and a sphere, and typically the weight of a gum center may be 0.5to 7 grams.

The following examples are given for illustration, but not limitation ofthe invention.

EXAMPLE 1 Preparation of Elastomer Solvent Hybrid Polyester Polymer byBlock-Polymerization

A resin (elastomer solvent) sample was produced via a two-stage processinvolving a transesterification/polycondensation reaction to synthesizea polyester prepolymer and a subsequent ring-opening polymerizationreaction to create the final block copolymer.

The polyester prepolymer was produced using a 4-necked 2 L resin kettleequipped with a heating mantle, overhead stirrer, nitrogen gas inlettube, thermometer, and distillation head incorporating a graduatedreceiver for removal and quantification of condensates. To the kettlewere charged 126.22 g (0.65 mole) dimethyl terephthalate, 51.15 g (0.35mole) dimethyl succinate, 68.27 g (1.10 mole) ethylene glycol, and 0.074g (0.03% w/w of reactants) fascat 9100. Under nitrogen, the mixture wasslowly heated with stirring until all components became molten (150-170°C.). Heating and stirring were continued at approximately 170° C. atatmospheric pressure under nitrogen, and methanol was continuouslydistilled until approximately the theoretical amount had been collected.The methanol was drained from the receiver; then a moderate vacuum (100mm Hg) was applied to begin collection of excess ethylene glycol. Thevacuum was gradually increased until a final vacuum of 0.200 mm Hg wasachieved. The temperature rose during this period but did not exceed185° C. The reaction was kept under these conditions until approximately1.6 mL of EG was collected. Then, the progress of polycondensation washalted by increasing the pressure to atmospheric and removal of thekettle from the heating mantle.

When the reactor contents had cooled to approximately 90° C., a solutioncontaining 200 g (1.39 mole) D,L-lactide dissolved in 360 g anhydroustoluene was charged to the flask. The resin kettle was then submerged ina 90° C. constant-temperature silicone oil bath, and the contents wereallowed to reach thermal equilibrium. Then, 0.28 g (0.038% w/w ofreaction mass) of Sn(Oct)₂ catalyst was introduced into the reactor.Reaction was allowed to proceed with periodic removal of aliquots untilSEC analysis of the aliquots showed that the D,L-lactide conversion wasabove 90 percent. The viscous liquid was allowed to cool to roomtemperature, and then precipitated into a 10 volume excess of cold, drymethanol. The precipitate was collected by filtration, washed with ofcold methanol, and dried under a vacuum at room temperature for 72 h.

Characterization of the product indicated M_(n)=4,940 g/mole andM_(w)=9,750 g/mole (gel permeation chromatography with online MALLSdetector), and Tg=30° C. (DSC, heating rate 10° C./min).

EXAMPLE 2 Preparation of Elastomer Hybrid Polyester Polymer byBlock-Polymerization

A polyester prepolymer was produced using a 4-necked 2 L resin kettleequipped with a heating mantle, overhead stirrer, nitrogen gas inlettube, thermometer, and distillation head incorporating a graduatedreceiver for removal and quantification of condensates. To the kettlewere charged 29.13 g (0.15 mole) dimethyl terephthalate, 148.06 g (0.85mole) dimethyl adipate, 108.24 g (1.02 mole) di(ethylene glycol) and0.086 g (0.03% w/w of reactants) fascat 9100. Under nitrogen, themixture was slowly heated with stirring until all components becamemolten (150-170° C.). Heating and stirring were continued atapproximately 170° C. at atmospheric pressure under nitrogen, andmethanol was continuously distilled until approximately the theoreticalamount had been collected. The methanol was drained from the receiver;then a moderate vacuum (100 mm Hg) was applied to begin collection ofexcess ethylene glycol. The vacuum was gradually increased until a finalvacuum of 0.200 mm Hg was achieved. The temperature rose during thisperiod but did not exceed 185° C. The reaction was kept under theseconditions until production of EG had ceased. Then, the progress ofpolycondensation was halted by increasing the pressure to atmosphericand removal of the kettle from the heating mantle.

When the reactor contents had cooled to approximately 90° C., a solutioncontaining 73.1 g (0.51 mole) D,L-lactide dissolved in 650 g anhydroustoluene was charged to the flask. The resin kettle was then submerged ina 90° C. constant-temperature silicone oil bath, and the contents wereallowed to reach thermal equilibrium. Then, 0.36 g (0.038% w/w ofreaction mass) of Sn(Oct)₂ catalyst was introduced into the reactor.Reaction was allowed to proceed with periodic removal of aliquots untilSEC analysis of the aliquots showed that the D,L-lactide conversion wasabove 90 percent. The viscous liquid was allowed to cool to roomtemperature, and then precipitated into a 10 volume excess of cold, drymethanol. The precipitate was collected by filtration, washed with ofcold methanol, and dried under a vacuum at room temperature for 72 h.

Characterization of the product indicated M_(n)=46,700 g/mole andM_(w)=93,300 g/mole (gel permeation chromatography with online MALLSdetector) and T_(g)=−31° C. (DSC, heating rate 10° C./min).

EXAMPLE 3 Preparation of Elastomer Solvent Hybrid Polyester Polymer byRandomized Polymerization

A resin (elastomer solvent) sample was produced using a 4-necked 1 Lresin kettle equipped with an overhead stirrer, nitrogen gas inlet tube,thermometer, and distillation head incorporating a graduated receiverfor removal and quantification of condensates. To the kettle werecharged, tinder nitrogen purge, 68.27 g (1.10 mole) ethylene glycol, 180g (1.25 mole) D,L-lactide, and 0.094 g (0.038% w/w of reaction mass) ofSn(Oct)₂. The resin kettle was submerged in a 130° C.constant-temperature silicone oil bath and stirred for 5 h. The kettlewas removed from the oil bath and fitted with a heating mantle. To thecontents of the kettle were added, under nitrogen purge, 126.22 g (0.65mole) dimethyl terephthalate, 51.15 g (0.35 mole) dimethyl succinate,and 0.13 g (0.03% w/w of reactants) fascat 9100. (150-170° C.). Undernitrogen, the mixture was slowly heated with stirring until allcomponents became molten (150-170° C.). Heating and stirring werecontinued at approximately 170° C. at atmospheric pressure undernitrogen, and methanol was continuously distilled until approximatelythe theoretical amount had been collected. The methanol was drained fromthe receiver; then a moderate vacuum (100 mm Hg) was applied to begincollection of excess ethylene glycol. The vacuum was gradually increaseduntil a final vacuum of 0.200 mm Hg was achieved. The temperature roseduring this period but did not exceed 185° C. The reaction was keptunder these conditions until approximately 1.6 mL of EG was collected.Then, the progress of polycondensation was halted by increasing thepressure to atmospheric and discontinuance of heating. The moltenpolymer was carefully poured into a receiving vessel and used withoutfurther purification.

Characterization of the product indicated M_(n)=5,230 g/mol andM_(w)=10,500 g/mol and T_(g)=28° C. (DSC, heating rate 10° C./min).

EXAMPLE 4 Preparation of Elastomer Hybrid Polyester Polymer byRandomized Polymerization

An elastomer sample was produced using a 4-necked 1 L resin kettleequipped with an overhead stirrer, nitrogen gas inlet tube, thermometer,and distillation head incorporating a graduated receiver for removal andquantification of condensates. To the kettle were charged, undernitrogen purge, 108.24 g (1.02 mole) di(ethylene glycol), 65.8 g (0.46mole) D,L-lactide, and 0.066 g (0.038% w/w of reaction mass) ofSn(Oct)₂. The resin kettle was submerged in a 130° C.constant-temperature silicone oil bath and stirred for 5 h. The kettlewas removed from the oil bath and fitted with a heating mantle. To thecontents of the kettle were added, under nitrogen purge, 29.13 g (0.15mole) dimethyl terephthalate, 148.06 g (0.85 mole) dimethyl adipate, and0.11 g (0.03% w/v of reactants) fascat 9100. (150-170° C.). Undernitrogen, the mixture was slowly heated with stirring until allcomponents became molten (150-170° C.). Heating and stirring werecontinued at approximately 170° C. at atmospheric pressure undernitrogen, and methanol was continuously distilled until approximatelythe theoretical amount had been collected. The methanol was drained fromthe receiver; then a moderate vacuum (100 mm Hg) was applied to begincollection of excess ethylene glycol. The vacuum was gradually increaseduntil a final vacuum of 0.200 mm Hg was achieved. The temperature roseduring this period but did not exceed 185° C. The reaction was keptunder these conditions until production of EG had ceased. Then, theprogress of polycondensation was halted by increasing the pressure toatmospheric and discontinuance of heating. The molten polymer wascarefully poured into a receiving vessel and used without furtherpurification.

Characterization of the product indicated M_(n)=47,100 g/mol andM_(w)=95,400 g/mol and T_(g)=−30° C. (DSC, heating rate 10° C./min).

EXAMPLE 5 Preparation of Gum Bases and Chewing Gums

Different gum bases are prepared from the above polymers by combiningelastomer solvent polymers of examples 1 or 3 with elastomer polymers ofexamples 2 or 4 as outlined in tables 1 and 2:

TABLE 1 % denotes percent by weight of the gum base. The ratio ofelastomer solvent/elastomer could be changed to for example 30%/70%,50%/50% etc. depending on the desired elastomeric and resinousproperties of the gum base. Gum base no. Composition 101 102 103 104 40%elastomer Polymer of Polymer of Polymer of Polymer of solvent ex. 1 ex.1 ex. 3 ex. 3 60% elastomer Polymer of Polymer of Polymer of Polymer ofex. 4 ex. 2 ex. 4 ex. 2

TABLE 2 % denotes percent by weight of the gum base. Different ratios ofelastomer solvent/elastomer could be used depending on the desiredelastomeric and resinous properties of the gum base. Gum base no.Composition 105 106 107 108 20% elastomer Polymer of Polymer of solventex. 1 ex. 1 20% elastomer Polymer of Polymer of solvent ex. 3 ex. 3 40%elastomer Polymer of Polymer of solvent ex. 1 ex. 3 60% elastomerPolymer of Polymer of ex. 2 ex. 4 30% elastomer Polymer of Polymer ofex. 2 ex. 2 30% elastomer Polymer of Polymer of ex. 4 ex. 4

The gum bases are prepared as follows:

The elastomeric polymer and resinous polymer are added to a mixingkettle provided with mixing means like e.g. horizontally placed Z-shapedarms. The kettle has been preheated for 15 minutes to a temperature ofabout 60-80° C. The mixture is mixed for 10-20 minutes until the wholemixture becomes homogeneous. The mixture is then discharged into the panand allowed to cool to room temperature from the discharged temperatureof 60-80° C.

The gum bases no. 101, 102, 103, 104, 105, 106, 107, and 108 are used inthe different chewing gum formulations shown in table 3:

TABLE 3 % denotes percent by weight of the chewing gum. Various furtherformulations could be prepared. Chewing gum no. Components A B C D E Gumbase 32%  32%  32%  40%  28%  Sorbitol 44.6%   43.6%   49.6%   36.1%  46.6%   Xylitol 6% 6% 6% 6% 6% Filler 5% 5% 0% 5% 6% Wax 4% 4% 4% 4% 4%Softener 2% 2% 2% 2% 2% Maltitol syrup 3% 3% 3% 3% 3% Peppermint 1.5%  0.5%   1.0%   1.0%   2.5%   Chocolate 2.0%   Liquorice 0.5%   1.0%  Emulsifier 1% 1% 1% 1% 1% Menthol crystals 0.5%   0.5%   0.5%   0.5%  0.5%   Aspartame 0.2%   0.2%   0.2%   0.2%   0.2%   Acesulfame 0.2%  0.2%   0.2%   0.2%   0.2%  

The softeners, emulsifiers and fillers may alternatively be added to thepolymers as a part of the gum base preparation.

The chewing gum products are prepared as follows:

The gum base is added to a mixing kettle provided with mixing means likee.g. horizontally placed Z-shaped arms. The kettle has been preheatedfor 15 minutes to a temperature of about 40-60° C. or the chewing gum ismade in one step, immediately after preparation of gum base in the samemixer where the gum base and kettle has a temperature of about 60-80° C.

One half portion of the sorbitol is added together with the gum base andmixed for 3 minutes. Peppermint and menthol are then added to the kettleand mixed for 1 minute. The remaining half portion of sorbitol is addedand mixed for 1 minute. Maltitol syrup is added, and then wax and fillermay be added and the gum mass is mixed well. Softeners are slowly addedand mixed for 7 minutes. Then aspartame and acesulfame are added to thekettle and mixed for 3 minutes. Xylitol is added and mixed for 3minutes. The resulting gum mixture is then discharged and e.g.transferred to a pan at a temperature of 40-48° C. The gum is thenrolled and scored into cores, sticks, balls, cubes, and any otherdesired shape, optionally followed by coating and polishing processesprior to packaging.

Evidently, within the scope of the invention, other processes andingredients may be applied in the process of manufacturing the chewinggum.

The provided chewing gum according to the invention has advantageoustextural properties. Moreover, the provided chewing gum is advantageouswith respect to both biodegradability and elastomeric properties.

1. Chewing gum comprising at least one chewing gum polyester polymer,wherein at least a first part of said polyester polymer is obtainable bycondensation polymerization and at least a further part of saidpolyester polymer is obtainable by ring-opening polymerization. 2.Chewing gum according to claim 1, wherein said at least one polyesterpolymer is at least partly biodegradable.
 3. Chewing gum according toclaim 1, wherein said condensation polymerization is based onpolyfunctional monomers selected from the group consisting of alcoholsand acids.
 4. Chewing gum according to claim 1, wherein saidcondensation polymerization is based on polyfunctional monomers selectedfrom the group consisting of alcohols, carboxylic acids,hydroxycarboxylic acids, or a derivative thereof.
 5. Chewing gumaccording to claim 1, wherein said ring-opening polymerization is basedon cyclic ester monomers, cyclic carbonate monomers or a combinationthereof.
 6. Chewing gum according to claim 1, wherein at least one ofsaid monomers is di-functional.
 7. Chewing gum according to claim 1,wherein at least one of said monomers is at least tri-functional. 8.Chewing gum according to claim 1, wherein the molar ratio between themonomers forming said first and further part of the polyester polymer iswithin the range of 1:1000 and 1000:1 by weight.
 9. Chewing gumaccording to claim 1, wherein the monomers forming said first part ofthe polyester polymer comprises a molar content within the range of 1 to99% of said polyester polymer.
 10. Chewing gum according to claim 1,wherein the monomers forming said further part of the polyester polymercomprises a molar content within the range of 1 to 99% of said polyesterpolymer.
 11. Chewing gum according to claim 1, wherein said at least onechewing gum polyester polymer forms the sole polymer of the chewing gum.12. Chewing gum according to claim 1, wherein said first part of the atleast one polyester polymer comprises a molar content within the rangeof 30 to 90% of said polyester polymer.
 13. Chewing gum according toclaim 1, wherein said first part of the polyester polymer compriseswithin the range of 30 to 90% by weight of said polyester polymer. 14.Chewing gum according to claim 1, wherein said at least one chewing gumpolyester polymer forms one of further polymers of the chewing gum. 15.Chewing gum according to claim 1, wherein said at least one chewing gumpolyester polymer forms one of further polyester polymers of the chewinggum.
 16. Chewing gum according to claim 1, wherein said first part ofthe at least one polyester polymer comprises a molar content within therange of 1 to 70% of said polyester polymer.
 17. Chewing gum accordingto claim 1, wherein said first part of the polyester polymer compriseswithin the range of 1 to 70% by weight of said polyester polymer. 18.Chewing gum according to claim 1 wherein said first part of the at leastone polyester polymer comprises a molar content within the range of 40to 99% of said polyester polymer.
 19. Chewing gum according to claim 1,wherein said first part of the polyester polymer comprises within therange of 40 to 99%, by weight of said polyester polymer.
 20. Chewing gumaccording to claim 1, wherein said at least one polyester polymercomprises a polyester selected from the group consisting of copolymers,terpolymers, quaterpolymer, graftpolymers, blockpolymers, randomizedpolymers, and combinations thereof.
 21. Chewing gum according to claim1, wherein said at least one polyester polymer comprises a blockcopolymer or a randomized copolymer.
 22. Chewing gum according to claim1, wherein said at least one polyester copolymer has at least two glasstransition temperatures.
 23. Chewing gum according to claim 1, whereinsaid at least one polyester copolymer has a single glass transitiontemperature.
 24. Chewing gum according to claim 1, wherein saidpolyfunctional alcohol monomers are selected from the group consistingof glycols, glycerols, polyglycols and polyglycerols.
 25. Chewing gumaccording to claim 1, wherein said polyfunctional alcohol monomerscontain 2 to 100 carbon atoms in the main chain.
 26. Chewing gumaccording to claim 1, wherein said polyfunctional alcohol monomers areselected from the group consisting of ethylene glycol, 1,2-propanediol,1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol,diethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol,neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol,sorbitol, mannitol, and mixtures thereof.
 27. Chewing gum according toclaim 1, wherein said polyfunctional alcohol derivative monomers areselected from the group consisting of triacetin, glycerol palmitate,glycerol sebacate, glycerol adipate, tripropionin, and mixtures thereof.28. Chewing gum according to claim 1, wherein said polyfunctionalcarboxylic acid monomers are selected from the group consisting ofsaturated, unsaturated, aliphatic, or aromatic polyfunctional carboxylicacids, or combinations thereof.
 29. Chewing gum according to claim 1,wherein said polyfunctional carboxylic acid monomers contain 2 to 100carbon atoms in the main chain.
 30. Chewing gum according to claim 1,wherein said polyfunctional carboxylic acid monomers are selected fromthe group consisting of oxalic acid, malonic acid, citric acid, succinicacid, malic acid, tartaric acid, fumaric acid, maleic acid, glutaricacid, glutamic acid, adipic acid, glucaric acid, pimelic acid, subericacid, azelaic acid, sebacic acid, dodecanedioic acid, cyclopropanedicarboxylic acid, cyclobutane dicarboxylic acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid,trimellitic acid, pyromellitic acid, naphthalene 1,4-, 2,3-,2,6-dicarboxylic acids, and mixtures thereof.
 31. Chewing gum accordingto claim 1, wherein said polyfunctional carboxylic acid derivativemonomers are selected from the group consisting of hydroxy acids,esters, anhydrides, or halides of carboxylic acids, and mixturesthereof.
 32. Chewing gum according to claim 1, wherein saidpolyfunctional carboxylic acid derivative monomers are selected from thegroup consisting of 3-hydroxy propionic acid, 6-hydroxycaproic acid,dimethyl or diethyl oxalate, dimethyl or diethyl malonate, dimethyl ordiethyl succinate, dimethyl or diethyl fumarate, dimethyl or diethylmaleate, dimethyl or diethyl glutarate, dimethyl or diethyl adipate,dimethyl or diethyl pimelate, dimethyl or diethyl suberate, dimethyl ordiethyl azelate, dimethyl or diethyl sebacate, dimethyl or diethyldodecanedioate, dimethyl or diethyl terephthalate, dimethyl or diethylisophthalate, dimethyl or diethyl phthalate, and mixtures thereof. 33.Chewing gum according to claim 1, wherein said ring-openingpolymerisation is based on cyclic monomers selected from the groupconsisting of glycolides, lactides, lactones, cyclic carbonates andmixtures thereof.
 34. Chewing gum according to claim 1, wherein saidlactide monomers are selected from the group consisting of L-lactide,D,L-lactide, and mesolactide, and combinations thereof.
 35. Chewing gumaccording to claim 1, wherein said lactone monomers are selected fromthe group consisting of ε-caprolactone, δ-valerolactone,γ-butyrolactone, and β-propiolactone, and mixtures thereof.
 36. Chewinggum according to claim 1, wherein said cyclic carbonate monomers areselected from the group consisting of trimethylene carbonates,dioxanones, ethylene carbonates, propylene carbonates, monocabonates,dioxepanones, and mixtures thereof.
 37. Chewing gum according to claim1, wherein said chewing gum comprises one or more chewing gumingredients selected from the group consisting of flavoring agents,sweetening agents, fillers, softeners, emulsifiers, and activeingredients.
 38. Chewing gum according to claim 1, wherein saidflavoring agents comprise natural and synthetic flavorings in the formof natural vegetable components, essential oils, essences, extracts,powders, including acids and other substances capable of affecting thetaste profile.
 39. Chewing gum according to claim 1, wherein saidchewing gum comprises flavor in an amount of 0.01 to about 25 wt %, saidpercentage being based on the total weight of the chewing gum. 40.Chewing gum according to claim 1, wherein the chewing gum comprises atleast one softener in an amount of about 0 to about 20% by weight of thechewing gum.
 41. Chewing gum according to claim 1, wherein the amount ofemulsifier is in the range of 0 to 18% by weight of the chewing gum. 42.Chewing gum according to claim 1, wherein said sweetening agents areselected from the group consisting of bulk sweeteners, and highintensity sweeteners, and combinations thereof.
 43. Chewing gumaccording to claim 1, wherein the chewing gum comprises sugar. 44.Chewing gum according to claim 1, wherein the chewing gum is sugar free.45. Chewing gum according to claim 1, wherein said bulk sweetenerscomprises an amount of about 5 to about 95% by weight of the chewinggum.
 46. Chewing gum according to claim 1, wherein the chewing gumcomprises high intensity sweeteners in an amount of about 0 to about1.2% by weight of the chewing gum.
 47. Chewing gum according to claim 1,wherein the chewing gum comprises filler in an amount of about 0 toabout 50% by weight of the chewing gum.
 48. Chewing gum according toclaim 1, wherein the chewing gum comprises at least one coloring agent.49. Chewing gum according to claim 1, wherein said chewing gumingredients comprise active ingredients.
 50. Chewing gum according toclaim 1, wherein said chewing gum is coated with an outer coatingselected from the group consisting of hard coating, soft coating andedible film-coating.
 51. Chewing gum according to claim 1, wherein theouter coating comprises at least one additive component selected fromthe group consisting of a binding agent, a moisture absorbing component,a film forming agent, a dispersing agent, an antisticking component, abulking agent, a flavouring agent, a coloring agent, a pharmaceuticallyor cosmetically active component, a lipid component, a wax component, asugar, an acid and an agent capable of accelerating the after-chewingdegradation of the degradable polymers.
 52. Chewing gum according toclaim 1, wherein said chewing gum polyester polymer is obtainable bysaid condensation polymerization performed first and said ring-openingpolymerization performed afterwards.
 53. Chewing gum according to claim1, wherein said chewing gum polyester polymer is obtainable by saidcondensation polymerization and said ring-opening polymerizationperformed randomized.
 54. Chewing gum according to any of the claimsclaim 1, wherein said polyester polymer is obtained by a combination ofcondensation polymerization and ring-opening polymerization.
 55. Chewinggum according to claim 1, wherein at least a first part of the monomersof said polyester polymer are polymerized by condensationpolymerization, and wherein at least a further part of the monomers ofsaid polyester polymer are polymerized by ring-opening polymerization.56. Method of obtaining a chewing gum polyester polymer, whereincondensation polymerization and ring-opening polymerization arecombined.
 57. Method of obtaining a chewing gum according to claim 1,wherein the polyester polymer is obtained through a combinedcondensation polymerization and ring-opening polymerization.
 58. Methodof obtaining a chewing gum polyester polymer according to claim 56,wherein the polyester polymer is obtained through a combinedcondensation polymerization and ring-opening polymerization.
 59. Methodof obtaining a chewing gum polyester polymer according to claim 56,whereby said condensation polymerization and said ring-openingpolymerization are performed subsequently.
 60. Method of obtaining achewing gum polyester polymer according to claim 56, whereby saidcondensation polymerization is carried out to prepare a prepolymer,wherein the prepolymer is used for initiation of a ring-openingpolymerization.
 61. Method of obtaining a chewing gum polyester polymeraccording to claim 56, whereby said condensation polymerization and saidring-opening polymerization are performed randomized.